This invention relates to portable vacuum cleaners, and especially to the type referred to as "wet/dry" vacuum cleaners, which are capable of picking up not only solid matter, such as dust, dirt and other dry debris, but also liquid or semi-liquid material. More particularly, the invention relates to wet/dry vacuum cleaners that are capable of pumping out the liquid solution in the tank in order to empty the recovered solution. The invention provides a valve for controlling the blower system in such a way that the exhaust air can be redirected back into the tank to apply pressure and pump the solution in the tank out through a tube that extends from the vacuum hose inlet to the bottom of the tank.
Wet/dry vacuum cleaners are used for a variety of purposes, such as the extraction of liquid used in the cleaning of floors, carpets, upholstery, etc. In these vacuum units, the liquid is sucked into a tank through a vacuum hose and it accumulates progressively in the collection tank during the operation. The dumping of the dirty liquid with its accumulated dirt and debris poses a problem since in many cases, the cover of the cleaner must be removed and the tank manually lifted and tilted on a sink or basin in order to dump the liquid solution. In other cases, the wet/dry vacuum cleaner is provided with a separate pump for evacuating the liquid solution. This is more costly to produce and requires additional maintenance.
In some current models, the dirty liquid is pumped out by reversing the connections for the vacuum blower in such a way that instead of exhausting air from the collection chamber in order to create a vacuum, exhaust air which normally exits through an exhaust fitting on the blower is applied to the tank so as to force the dirty solution through a tube that extends to a position close to the bottom of the tank. In this way, the liquid in the tank is pumped out through the inlet fitting for the vacuum system.
It is among the objects of the present invention to provide a vacuum pump-out control valve for a wet/dry vacuum cleaner that permits pressure from the vacuum blower to be applied to the liquid-filled collection tank.
Another object of the invention is to provide a unique rotating valve in a vacuum pump-out system for a wet/dry vacuum cleaner that may be easily switched back and forth between a normal, vacuum position and a pressure applying, pump-out position.